Pauses for 2 minutes in between rendering animation frames
Blender is not pausing between rendered frames: its generating the curent frame, and sometimes it can take a long time to calculate all the information needed to start rendering. 

3D rendering can be one of the most compute-intensive operations you can throw at a computer. With very little effort you can create scenes that will push your system to its limits. 

You are probably taxing your system with a scene that has:


Lots of particles
Physics Simulations
Lots of vertices (either from complex/detailed objects, or from
vertices created by modifiers, like subsurf modifier or arrays).
Volumetrics (volume scattering and/or volume absortion).
All or some of the above, and maybe even other layers of
complexity...


You have the option to:


Wait
Optimize your scene
Split the rendering load on different computers (like a Render Farm)


You might be able to find what process is taking so long by checking the top of the UV/Image editor window while rendering:



Things you can do to make the scene more friendly and renderable within your lifetime?


Simplify the geometry: decimate or re-topologize.
Use smaller textures. Textures shouldn't be any larger than the size
they are going to be on the final render.
Bake textures and lighting if possible.
Cache simulations and particles to disk and/or bake all dynamics,
so that the computer doesn't have to compute them again for every
frame.
Keep your subsurf levels as low as you can, no more than 3... read
this post.
Find the optimal tile size for your system
Keep the render samples as low as you can, set them to a noise level
you can live with, remember for animation not all frames have to be
as perfect as a still image.
Split the scene in different render layers that render efficiently,
and composite them together into a final scene.


Avoid rendering directly to video formats: if your computer crashes you'd have to stat over! Always render as image sequences and encode to video afterwards.

Lastly (an option that been deprecated but might still be available on older versions of blender), for geometry that does not change through the scene: cache BVH.